DE 197 15 360 A1 describes an operating device including an actuator formed as a knurled roller rotatably mounted on a bearing block. The bearing block and a printed circuit board (PCB) clipped thereto are immovably connected to one another. The actuator is rigidly arranged with respect to motions perpendicular to its axis of rotation with respect to the bearing block and a substrate. A switch arranged on the substrate is supported against a separate housing such that a pressure actuation of the actuator is transmittable to the switch. The mounted assembly made up of the actuator, the bearing block, and the PCB is movably supported with respect to the housing.
The operating device further includes a detent wheel and a spring-loaded detent. The detent wheel is connected with the actuator and includes recesses into which the detent penetrates. In the absence of pressure actuation, the rotational motion of the detent wheel is not affected by the actuator.
For many applications it is desirable that a rotationally actuated operating element have perceptible detent levels. A detent wheel with an undulating detent contour is provided for this purpose against which a spring-loaded detent pin presses.
A rotational actuation of the operating element with detent steps does not follow from DE 197 15 360 A1 since the detent that penetrates into the openings of the detent wheel here allows only a blockage or release of the actuator. Additional means would thus be required to achieve interrupted rotation of the operating element. Such additional means would require additional cost expenditures and a larger installation space.